Depth analysis of technology, market and enterprise of electric vehicle motor and drive system
First, motor controller technology and market
Battery technology, motor drive and its control technology, energy management technology and electric vehicle technology are the four key technologies of electric vehicles. The electronic control system is used to control components such as batteries and motors. Its functions include: battery management, engine and motor energy management.
The electronic control system is composed of a control system such as an ECU, a sensing system such as a sensor, and a driver's intention identification system. The material cost of the electronic control system is not high, but it takes a lot of trials to master the key algorithms. Especially the hybrid vehicle involves the control strategy of oil and electricity mixing, and the technical barriers are high.
As the power conversion unit connecting the battery and the motor in the new energy vehicle, the motor controller is the core of the motor drive and control system. It mainly includes the hardware parts such as the IGBT power semiconductor module and its associated circuit, as well as the software part of the motor control algorithm and logic protection.
The motor drive control system (including the drive motor and motor controller) is the main execution structure in the operation of new energy vehicles. The control and drive characteristics determine the main performance indicators of the vehicle.
Generally speaking, the motor controller is mainly composed of the following parts:
1. The electronic control module (ElectronicController) includes hardware circuits and corresponding control software. The hardware circuit mainly includes the microprocessor and its minimum system, the monitoring circuit for the state of the motor current, voltage, speed, temperature, etc., various hardware protection circuits, and the data interaction with the external control unit such as the vehicle controller and the battery management system. Communication circuit. The control software implements the corresponding control algorithm according to the characteristics of different types of motors.
2. The driver converts the control signal of the microcontroller to the motor to drive the driving signal of the power converter, and isolates the power signal and the control signal.
3. The power converter module (PowerConverter) controls the motor current. Power devices often used in electric vehicles include high-power transistors, gate turn-off thyristors, power FETs, insulated gate bipolar transistors, and smart power modules.
Motor controller appearance structure
At present, the electric motor controllers of the electric vehicles mostly adopt three-phase full-bridge voltage-type inverter circuit topology, and some products have pre-directional bidirectional DC/DC converters to increase the input AC voltage of the motor end, increase the output power at high speed, and reduce the motor. Design and production costs. In the conventional controller, the DC supporting capacitor is bulky and has poor high temperature resistance.
In order to reduce the volume of DC supporting capacitors and even eliminate DC supporting capacitors, the new converter circuit topology and control method have become a new hotspot in electric vehicle application research, but it is still in the stage of practical exploration.
At present, the research and development focus of converters for electric vehicles is still concentrated on power electronics integration.
Comprehensive technology and market trend analysis, in the future, the three technological development directions of automotive drive motor systems are permanent magnetization, digitization and integration.
1. Permanent magnetization means that the permanent magnet motor has the advantages of high power density and torque density, high efficiency and easy maintenance. At present, the trend of permanent magnetization of the motor is prominent. According to the consultation data, the permanent magnet synchronous motor has accounted for more than 90% of the use of new energy vehicles in China.
2. Digitization includes digitization of drive control, digitization of drive to CNC system interface, and digitization of measurement unit. The software replaces the hardware to the greatest extent, with other functions such as protection, fault monitoring, and self-diagnosis.
3, integration is mainly reflected in two aspects: 1) motor: motor and engine assembly, motor and gearbox assembly integration; 2) controller: power electronics assembly (power devices, drive, control, Integration of sensors, power supplies, etc.) In the future, the integration of motors, reducers and controllers is a trend that not only reduces the size, but also makes the products more standardized.
As the new energy vehicle market will continue to improve in the next few years, the market potential in this field will gradually be released, and the market size of the motor controller will gradually increase. At present, the price of passenger car motor controller is generally 30,000 to 50,000 yuan, and the price of passenger car motor controller is generally 0.6 to 15,000 yuan.
Through calculations, it is estimated that by 2020, the market size of domestic new energy vehicle motor controllers will exceed 15 billion yuan. (For detailed calculation, please refer to the “2016-2020 China New Energy Automobile Motor and Controller Market Investment Report” published by the public.
2016-2020 China New Energy Automotive Motor Controller Market Size (100 million yuan)
In the supply chain, the development of motor controllers includes software and hardware design. The core software is generally developed by the OEM, and the hardware and the underlying driver software can be selected by the auto parts manufacturer.
China's controller hardware level has a certain gap with foreign countries, and the industrialization capacity is relatively insufficient. Most companies are more inclined to choose foreign vehicle controller hardware suppliers when they introduce mass-produced electric vehicle products.
In addition, the controller's basic hardware, development tools, etc. basically rely on imports.
Motor controller industry chain situation
In terms of enterprise types, the current mainstream motor control enterprises are mainly divided into two categories: one is an electric vehicle manufacturer, and the electric vehicle motor controllers produced by them generally supply their complete vehicle products; the other is electric vehicle parts enterprises, The electric motor controllers produced are generally supplied to specific or non-specific vehicle companies.
In the field of passenger vehicles, vehicle companies usually have strong comprehensive strength. They usually develop and produce electric vehicle motor controllers independently, or mainly rely on independent research and development, and supplement the products of appropriate parts and components enterprises. In the field of passenger cars, Automobile companies usually have insufficient experience in motor controller research and development. Generally, they choose to purchase electric motor controllers. A small number of large-scale vehicle companies will choose independent research and development or independent research and development.
Although there are differences in controller technology at home and abroad, starting from 2015, new energy vehicle product types are diversified, and the demand for different controllers is more abundant. In terms of quantity alone, the current market for electric motor controllers in China is mainly occupied by domestic brands. Foreign-funded products account for a small share in the market cultivation and initial development stage due to their high prices.